mysqli_query() - Run SQL Queries

PHP Modules Tutorials - Herong's Tutorial Examples

∟mysqli_query() - Run SQL Queries

This section provides a tutorial example on how to run a SQL query on a MySQL server by calling the mysqli_query() function.

Once you have created a MySQL connection, you can run SQL queries using the mysqli_query() function:

 
$res = mysqli_query($con, $sql);

where:
  $con - The MySQL connection object
  $sql - The SQL query statement string 
  $res - The query execution result

Ther are several other functions related to mysqli_query():

mysqli_error($con) - Returns the error message from the query
mysqli_errno($con) - Returns the error number from the query

Here is a PHP script example showing you how to use the mysqli_query() function:

<?php
#  mysqli-query.php
#- Copyright 2009-2026 (c) HerongYang.com. All Rights Reserved.

  $con = mysqli_connect("127.0.0.1", "herong", "TopSecret");

  # drop an existing database 
  $res = mysqli_query_err($con, "DROP DATABASE MyBase");

  # create a new database 
  $res = mysqli_query_err($con, "CREATE DATABASE MyBase");

  # set the current database 
  $res = mysqli_query_err($con, "USE MyBase");

  # create a new table
  $res = mysqli_query_err($con, 
    "CREATE TABLE MyTable ".
    "(ID INTEGER AUTO_INCREMENT, Value INTEGER, PRIMARY KEY (ID))");

  # query the table structure 
  $res = mysqli_query_err($con, "DESC MyTable");

  # display the header row 
  $fields = mysqli_fetch_fields($res);
  foreach ($fields as $field) {
    print(str_pad($field->name, 10));
  }
  print("\n");

  # display result rows
  while ($row = mysqli_fetch_array($res, MYSQLI_NUM)) {
    foreach ($row as $val) {
      print(str_pad($val, 10));
    }
    print("\n");
  }
  mysqli_free_result($res);

  mysqli_close($con);

function mysqli_query_err($con, $sql) {
  $res = mysqli_query($con, $sql);
  if (!$res) {
    $errno = mysqli_errno($con);
    $error = mysqli_error($con);
    print("Query failed: $errno - $error\n");
  }
  return $res;
}

If you run the script, you will get the following output:

herong$ php mysqli-query.php 

Query failed: 1008 - Can't drop database 'mybase'; 
  database doesn't exist

Field     Type      Null      Key       Default   Extra     
ID        int(11)   NO        PRI                 auto_increment
Value     int(11)   YES